Figure 7. Phthiocerol dimycocerosate (PDIM) and ESX modulate TLR2-dependent infection outcomes in macrophages and mice.

(A–C) The indicated bone marrow-derived macrophages (BMDM) were infected with the indicated Mycobacterium tuberculosis (Mtb) strains at an MOI of 5:1 (A–B) or 2:1 (C). (A–B) Cell survival was determined using a CellTiterGlo luminescence assay at the indicated days post-infection. (C) At day 5 post-infection, cells were washed, lysed, and plated for CFU. (A–C) Mean ± SD for four replicates. #p-value < 0.05, *p-value < 0.01 unpaired two-tailed t-test. (D) C57BL/6J or Tlr2-/- mice were infected with ~200 cfu of the indicated Mtb strains; 42 days post-infection, mice were euthanized and lungs were harvested and plated in serial dilutions to determine CFU Mean ± SD for five mice per condition (one C57BL6/ppsD plate discarded for mold contamination – four replicates for that condition). #p-value < 0.05, unpaired two-tailed t-test. (A–C) One of three independent experiments, (D) one of two independent experiments.

Figure 7—figure supplement 1. The indicated mouse strains were infected with the indicated Mycobacterium tuberculosis (Mtb) strains via low-dose aerosol infection.

(A) Lungs were harvested after infection and plated on day 0 for CFU. Mean ± SD for three to five mice per condition. (B–C) Lungs were fixed in formalin, embedded in paraffin, and sectioned. Sections were stained by hematoxylin and eosin and imaged on a TissueFACS Slide Scanner using a 20× objective. (B) Overview of all fields for a sectioned lung. (C) Individual fields of view for areas of cellular infiltration in each lung. Arrows: Areas of dense inflammatory cell infiltration. Arrow heads: areas of foamy macrophages. #p-value < 0.05, unpaired two-tailed t-test.